Recirculating fuel systems for forming a fuel-air mixture of the type in which a stream of induced air impinges upon a stream of fuel in a fuel dispersion gap or opening and wherein the air strips fuel from the stream are known in the art. For example, U.S. Pat. Nos. 3,785,627 granted to Tuzson, Hallberg and Vaughn on Jan. 15, 1974; 3,977,382 granted to Tuzson and Hallberg on Aug. 31, 1976; and 4,130,610 granted to Paul on Dec. 19, 1978 are examples of such fuel systems or charge forming apparatus. Each of the patents describe apparatus in which a throttle member controls the velocity of the air stream, which throttle member is of the peripheral opening type, i.e., the throttle member pivots about a diameter thereof; and the tubular member with the gap through which fuel is supplied is spaced above the opening zone of the throttle member.